Many older buildings and homes have plaster walls, with a metallic mesh that serves as the framework. This metal can interfere with the high-frequency radio signal, known as wireless fidelity, or WiFi, that is transmitted from a router.

Do walls interfere with WiFi signal?

Wi-Fi signals are most weakened by having to go through thick walls, especially reinforced concrete. See also: Wi-Fi Signal Loss by Building Material.

What materials can block a Wi-Fi signal?